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block: refactor bdrv_child_set_perm_safe() transaction action 

Old interfaces dropped, nobody directly calls
bdrv_child_set_perm_abort() and bdrv_child_set_perm_commit(), so we can
use personal state structure for the action and stop exploiting
BdrvChild structure. Also, drop "_safe" suffix which is redundant now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-35-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2021-04-28 18:18:02 +03:00 committed by Kevin Wolf
parent 4954aacea0
commit ecb776bd93
2 changed files with 22 additions and 46 deletions
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63
block.c
View File

@ -2135,59 +2135,40 @@ static GSList *bdrv_topological_dfs(GSList *list, GHashTable *found,
return g_slist_prepend(list, bs);
}
static void bdrv_child_set_perm_commit(void *opaque)
{
BdrvChild *c = opaque;
c->has_backup_perm = false;
}
typedef struct BdrvChildSetPermState {
BdrvChild *child;
uint64_t old_perm;
uint64_t old_shared_perm;
} BdrvChildSetPermState;
static void bdrv_child_set_perm_abort(void *opaque)
{
BdrvChild *c = opaque;
/*
* We may have child->has_backup_perm unset at this point, as in case of
* _check_ stage of permission update failure we may _check_ not the whole
* subtree. Still, _abort_ is called on the whole subtree anyway.
*/
if (c->has_backup_perm) {
c->perm = c->backup_perm;
c->shared_perm = c->backup_shared_perm;
c->has_backup_perm = false;
}
BdrvChildSetPermState *s = opaque;
s->child->perm = s->old_perm;
s->child->shared_perm = s->old_shared_perm;
}
static TransactionActionDrv bdrv_child_set_pem_drv = {
.abort = bdrv_child_set_perm_abort,
.commit = bdrv_child_set_perm_commit,
.clean = g_free,
};
/*
* With tran=NULL needs to be followed by direct call to either
* bdrv_child_set_perm_commit() or bdrv_child_set_perm_abort().
*
* With non-NULL tran needs to be followed by tran_abort() or tran_commit()
* instead.
*/
static void bdrv_child_set_perm_safe(BdrvChild *c, uint64_t perm,
uint64_t shared, Transaction *tran)
static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm,
uint64_t shared, Transaction *tran)
{
if (!c->has_backup_perm) {
c->has_backup_perm = true;
c->backup_perm = c->perm;
c->backup_shared_perm = c->shared_perm;
}
/*
* Note: it's OK if c->has_backup_perm was already set, as we can find the
* same c twice during check_perm procedure
*/
BdrvChildSetPermState *s = g_new(BdrvChildSetPermState, 1);
*s = (BdrvChildSetPermState) {
.child = c,
.old_perm = c->perm,
.old_shared_perm = c->shared_perm,
};
c->perm = perm;
c->shared_perm = shared;
if (tran) {
tran_add(tran, &bdrv_child_set_pem_drv, c);
}
tran_add(tran, &bdrv_child_set_pem_drv, s);
}
static void bdrv_drv_set_perm_commit(void *opaque)
@ -2367,7 +2348,7 @@ static int bdrv_node_check_perm(BlockDriverState *bs, BlockReopenQueue *q,
bdrv_child_perm(bs, c->bs, c, c->role, q,
cumulative_perms, cumulative_shared_perms,
&cur_perm, &cur_shared);
bdrv_child_set_perm_safe(c, cur_perm, cur_shared, tran);
bdrv_child_set_perm(c, cur_perm, cur_shared, tran);
}
return 0;
@ -2466,7 +2447,7 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
Transaction *tran = tran_new();
int ret;
bdrv_child_set_perm_safe(c, perm, shared, tran);
bdrv_child_set_perm(c, perm, shared, tran);
ret = bdrv_refresh_perms(c->bs, &local_err);

5
include/block/block_int.h
View File

@ -813,11 +813,6 @@ struct BdrvChild {
*/
uint64_t shared_perm;
/* backup of permissions during permission update procedure */
bool has_backup_perm;
uint64_t backup_perm;
uint64_t backup_shared_perm;
/*
* This link is frozen: the child can neither be replaced nor
* detached from the parent.